The present invention relates to an improvement in rotary valves of the tamper-proof type, and more specifically, to a gas meter valve which may be locked in a selected position which is usually the closed position of the valve. In an alternate embodiment, the valve can be locked in either a closed or opened position, as desired, in such a manner that access to the locking element will be virtually impossible without destroying the valve itself.
In a number of circumstances, suppliers of natural gas or other fluids are required to secure the distribution lines to prevent unauthorized access thereto such as in the case where a gas line is being installed prior to occupancy by a resident or where accounts become delinquent or where a residence has been vacated and will remain unoccupied for a period of time. Quite often, prior to reinstitution of the gas service, it is necessary for a worker from the gas company to make certain that the gas consuming devices in a dwelling are properly operating before the gas service is reinstituted.
While the prior art has provided a variety of fluid distribution valve locking devices, with the presently increasing costs of maintaining and delivering natural gas to customers' it has become necessary to make certain that unauthorized or unmetered access to the gas lines is prevented not only to loss to the supplier, but also to prevent prevent economic accidental leakage which can result is catastrophic explosions.
In designing locking elements for such valves, it has become apparent that the locking element itself must be made of high-strength material such as stainless steel or the like which, obviously, will increase the expense of such elements particularly where they must be replaced in the event they are damaged as a result of attempts to defeat the locking feature. Conversely, it is desirable that the locking element itself be employed in such a manner in the valve so that the locking element can be reused a number of times with a plurality of different valves as circumstances may warrant. Thus, it is important that the elements of the locking device of the valve be operated in such a manner they do not deface or alter the surfaces of the locking element which would render reuse of the locking element at a subsequent time difficult or impossible as a result of such alteration of the surface or inter-engaging portions of the locking element. Where a locking device is provided that can insure the integrity of the locking element, manufacturers can resort to the use of stronger and thus more expensive metals in the construction of the locking element. This will have the advantage that a more secure locking device can be employed in the gas distribution system.
It is, accordingly, an object of the present invention to provide a rotary valve with a locking device of a type where repeated operation of the locking device will not alter the condition of the locking element itself yet one which will provide, at a reasonable cost, a secure, tamper-proof locking of a valve in a selected position.
The locking device of the present invention will provide a secure locking of a valve element where the locking element itself will be isolated from tampering from the outside of the valve by tools that are commonly available as well as a tamperproof valve that will be substantially immune from breaking of the locking device without destroying the valve itself.
A still further object of the present invention is to provide a locking element for a tamperproof valve which can be easily operated a number of times over a period of years with a plunger-type key element which will insure that the locking bore of the valve without defacing or marring the surface of the locking element which would render subsequent use difficult or impossible.
To accomplish the foregoing objects, the rotary valve of the present invention is provided with a body member having a passage which is intersected by a plug seat. A ported valve plug member is rotatably mounted relative to the plug seat to be movable between open and closed positions, the valve plug having an end portion which terminates flush with or below the exterior of the valve member. One end of the plug member extends exteriorly of the housing and, as is conventional, is provided with an operating head to facilitate rotation of the plug such as by the application of a tool to the head. Between the operating head and the port of the valve body, a locking bore is provided and which extends through this portion of the valve body. The locking bore is provided with a first cylindrical portion of a selected diameter for receiving the body of a locking element, a second partially cylindrical portion which, according to the present invention, is also provided with a frustoconical surface which cooperates with a locking cage, described below. Adjacent the conical surface another cylindrical bore section is provided through which is inserted the cylindrical tip portion of the locking element. The cylindrical tip portion of the locking element is connected to the body portion by a reduced diameter neck portion which cooperates with the fingers of the locking cage to securely retain the locking element in its locked position. In this position, the tip portion of the locking element extends completely through its associated bore into a reinforced steel plug member which is located in a bore provided in the housing of the valve housing itself. A plunger-type key element is provided with a cylindrical end which is insertable into the locking bore surrounding the body of the locking element to engage and push back the fingers of the locking cage completely out of the path of travel of the tip portion of the locking element. The key element may be provided with a magnet in the handle thereof to enable it to retain the locking element to facilitate withdrawal of the locking element when it is desired to unlock the valve. The cylindrical portion of the key element is movable independently of the handle portion thereof. With this arrangement, insertion of the locking element into the locking bore will be easily effected by inserting the cylindrical portion of the key to cause the fingers of the cage to be resiliently pushed out of the path of travel of the locking element. Thereafter, the plunger and the cylindrical portion of the key can be withdrawn as the locking element will be retained in the locking bore by the fingers of the cage.
With this arrangement, alteration or defacing of any of the surfaces of the locking element will be substantially prevented thus ensuring smooth operation of the locking element over a number of uses and with a number of similarly fashioned locking devices of other rotary valves.
The foregoing and other advantages of the present invention will become apparent as consideration is given to the following detailed description taken in conjunction with the accompanying drawings, in which: